Arrangement for directional transmission and reception by means of electric waves



W. HAHNEMANN 1,764,441 ARRANGEMENT FOR DIRECTIONAL TRANSIIISSION ANDJune 17, 1930.

RECEPTION BY MEANS OF ELECTRIC WAVES Fililid y 1925 4 Sheets-Sheet lJune 17, 1930. w. HAHNEMANN 1,764,441 ARRANGEMENT FOR DIRECTIONALTRANSMISSION AND RECEPTION BY MEANS OF ELECTRIC WAVES Filed-July 28,1925 4 Sheets-Sheet 2 o o v *June17, 1930, W AHNEMANN 1,764,441

ARRANGEMENT FOR DIRECTIONAL TRANSMISSION AND RECEPTION BY- MEANS OFELECTRIC WAVES V Filed July 28, 1925 4 Sheets-Sheet 3 June 17;!930. w.HAHNEMANN 1,764,441 ARRANGEMENT FOR DIRECTIONAL TRANSMISSION ANDRECEPTION BY MEANS OF ELECTRIC WAVES Filed July 28, 1925 4 Sheets-Sheet4 dowowouon NQNQHOHQHONQHONOHVN fax ' WALT-ER iiAIiivni/iAnnor;iritrznnnnsgnnnni r The inventionrelatesto a nethod for di- Jun e- 117, i930 Iron nrnncrronnn TRANS n'LEc'riiro WAVES Application filed .iuijas, 1e25, seriaiivotaasee, and in Germany .4;". 9 4 s rectional'transmission and reception; by

from one another,

i ie'ans'of electric waves which is carried out A vvitlr severaltransmitting or receivingan'-I 5f tennae' arranged at a predetermineddistance preferably in a straight line. a

I g I "The object of the invention is to obtain as p I sharp as possiblea directional e'fiect by a plu-' 10 ra'lit'y oftransiiiitting orreceiving antennae located at definite distances apart from one" a 1another given by theory; 7 i r 5 ,tlieqsame?distai celi .Furthermore,-inthese screen made ofzwire is used.

J t y In contradistinctionto and as an f anent over these prior artdevices, I have found that when the; number of antennae which serve astransmitting and. receiving antennae proper, is increased, the distanceof i these antenna from eachother must be made dependent uponthe-"number ofthe antennae insed in order to obtain an optimum direci lli teniiae are arranged at certain distances from v -'eachI 0t-her; In-these prior art arrangements eitherfthe nuniberoftheg-antennaeused istoo small for i istancefonlyfi) in order t'oipro- 2 duceawelldefineddirectional efl ect, or else the distances'betweentheiantennae proposed w "as; advantageous are incorrect-in fact, in so'faiilas these prior art arrangementspropose feradiiiernt numbersofQantennzeused always z prior'artdevices the directional effect is not;variable,' in such; arrangements, for'instance,

" jin Which/only a transmitting'and receiving j antenna proper isusedand inwhich for pro-' jodu'c iig,v the CllIQCtlOIlLl; efi'ect astationary 'ti'onal eifect, this variable distance (Z between,rth'eantennae followingtlielawz a V r-1 ivvherein in idenotesithenumber of antennae, athegwave length of the signals transmittedor'received. I Y

The method according to the invention con- 7 sists in using more thantwo or three, in other ords-a multiplicity OfitllllSiIllttlIlgiOI re-Directional antennaaritangeinents have V ,5 ,been used heretofore forireless telegraphy 15 in yvl iclreitherjoi e antenna or several an-vimprove- Miss-Ion AND nncErrioiv: eenage s-7 0a").. i

ceiving: antennae which are" arranged v prefer;

order ofinagi itude berof antennaef r c I v For the generaljforimila" 1'in seaa eaewaaa a aha. m

tha "Shows; ma thisformuIas11ou1d 1 notbefmiich difierentlfromgn il ifthe re} quirement or as; sharp as possible directions f al eiiectjof thearrangementfis to be; obtained; If it; is greaterjth'anfn-;l,that'is'itoj say,- if

is approximately equal to' or even greater than n; then fthe auxiliaryniaxiina arising may become predominant, the directional aotion therebysuffers; if the spacing apart with reference to a is too "small, thatisto. saygif 7a is smaller than W{1,' the directionaleifect' is lo-stovving-to the individual transmitting-or receiving pointsbeingilocatedlrvvithin too a small a range inrelationto the wavelength,The'above Willbereadily understood-fron the Figuresl to 5 of thedrawingfilnthese' I vectors forfantennae arrangements are given fordifferent values of and gThe' vvector represents the amplitudes,ithejenergy' is; therefore proportional tofthe-square of these fvectors. lThe dotted straight line a 6 indi-Q cates theline on which aremounted. qt

Wavesorin pulses in the antennae and jiIi-proby means of time lagcircuits inserted between figures the gcurvesiffor the'flplanedirectional I 'ducingthe same directional effect in receiv jingelectrical waves in the {observers' station Z H79 the difierent'antennae andthe sourcefofelecr' ff f trical energy or the observersstation.""" Instead of makingnse-of ti ne lag Lcircuitsthe I sameefifect mayhe -obtainedbyproducing the 'properfrelation of phasei oftheifeedingcun 100 25 the di-fierent antennae rentfor theparticularantennae in'the source of the current itself.

'Another feature of the inventionconsists in shadowing away orreflecting and making use of one of the two rays of waves emitted by anarrangement according to the invention, or by a similar directionalarrangement.

The particularfeatures of the invention and some diagrams elucidatingsome theoreti-v cal points are shown in-the drawings WlllClL representsin s Figs. *1-5 different diagrams showing up the influence of thenumber of antennae and Figs. 12 andl? combinations of screensandantennae. p 7

, In Figure l, the case-is shown of two antennae in the optimum. case oflc= n-l=-1. Thedirectional action isstillflquite weak.-

In Figure2, a case of the invention is given where n=3, k nf i=2, Thedirectional effeet is already much better than in Figure 1. Laterally tothe direction of the main action, an auxiliary maximum of slightintensity occurs (about one tenth the energy of the main direction). v rV I v In Figure 3, n=3 and 70 3, that is chosen too large. Clearly theone auxiliary maximum has swollen to the value of the main maximum. Thedirectional effect-is therefore spoiled. V y

In Figure 4, n=3 and 70 1, that is chosen too small. 7 The gooddirectional action has been lost, the curve does not differ from Figure1,which is the arrangement with two antennae. a V i In order to showWhatinfluence the increase in the numberof antennae has, Figure 5 isgiven- Here the number n ofthe antennae is 5 and according to theinvention k=n1 is chosen as at. It is seen how much with five antennaecompared withthree antennae (Figure 2) the sharpness of the'directionalaction has been increased. It shows inthis case that a compromise willbe possible according to the prevailing practical conditions between thenumber of antennae and the sharpness of direction. 1

The figures are based for the case of transmission on excitation of theindividual antennae in the same phase. .Here they give the root of theratio of the amounts of energy radiated dependent uponthe angle to thebase of the arrangement; in the case of reception they'give the root ofthe ratio of the received energy of the total arrangement dependent uponthe angle of its base to the direction of the incoming field of electricwaves.

If ,thedifferent transmitting or receiving points are excited at thesame time min the same phase, this means that the maximum directionalaction is at right" angles to their connecting line. f v i The inventiongains a'general practical importance particularly by the additional factthat the maximum directional vector according to the invention is made,rotatable- This means may be applied accordingto the invention; notonly in cases of the before describedjkind but also for all kinds ofantennae arrangements in which thean-tennae are placed at a definitedistance from one another and a directional effect istobeproduced bymeans of time or phase displacement of the waves and impulses in theantennae. The relation-of the vector of .maximum, emission or receptionis attained by an arrangement whichlpermits for the different antennaepointssuch mutual time displacements of the oscillation phenomenon totake place as are necessary inorder to bring the main directional actioninto thedesired angle to the base. A suitable-means for carrying outthis feature of theinvention consists in the use'of time lag circuits,for instance in-the form of electric filter chain s, whose, adjust mentas regards their individual links is given on the one hand by thehighest employed frequency of. electric .oscillations and on the otherhand by the desired sharpness of graduation of the circularheld to beacted upon,

VVlnlst with the use of time lag circuits the correct phase relationinthe antennae is'eftennae. This can be achieved in a great manydifferent wa s, for example, by relativeshifting of the stator ofthe'main frequency machine, by arrangement of rotating fields withstationarywindings in which coils are rotatable or by the connecting-inof-self-induction coils, condensers and resistances or a combination ofthe same. 1

l "A practical application of the invention arises, for example, when itisn matter of saving as much energy as possible, for example, when theinternational wireless trafiic and communication is to be establishedforthe timebeing only with onest-ation in a perfeet-1y definite knowndirection with as little cost as possible and excluding as far aspossible interferences with other stations (transmission) or by otherstations (reception).

- placed from one another at definite distances 7 shown the drawing(Figs. ,6 and 9 to 13).

Beginning with 1 a directional antennae. ar-

rangement without screen this object. of-the invention is fullydescribed in the, following; In Figure 7 a plurality otantennae dis '20of such character that the undesiredvector-according to the well knownrule: angle of incidenceequal to angle of deflect1on-1s reflectedtowards the same direction as the desired maximum vector of direction, 7as shown by particular position of-tlie arrows 1 a, (1 ,1), .0, a to oneanother.

A' screenarrangement adapted for this effeet is shown in Fig. 9 and 10.The screen consists of a conducting wall comprising per-- pendicularsuspended conductors preferably. connected to; the earth, the thicknessof the screen arrangement amounting to about one wave-length (at leastone half wave-length) 40 the four posts 25.28. The carrying into efofthe oscillations used. The conducting wall contains a number of linesofconductors -24) displaced from one another some metres, The individualconductors preferably are so arranged, asshown in Fig. 10,

that the conductors of two neighbouring lines are displaced like thefieldsof achessboard.

Thewhol'e system of conductors is held by V 7 feet of the invention isnot at all questionable J for fear of too large dimensions of such anarrangement because nowadays preferably also for large distances use ismade of short wave-lengths. 7 f

The described screen arrangement acts substantially as a reflector. Itmay also be built 7 upof conductors consisting of tuned electricalcircuits arranged as is shown in'Figs. 9 and 10. These tuned circuitshaverto be damped substantially by radiation for thelpurpose ofire-emitting a substantial part of theimping- ,ing energy and ofabsorbingonly a small part.

An example of such an arrangement is shown in igxll. It differs from thereflector of Figs. 9 and 10 especially by the variable indnctances whichare inserted in the perpendicular suspended conductors 20'-24. Be-

' sides the lines of conductors in this case preferably are positionedfrom one another. at a distance amounting to about onewave-length (atleast one half'wave-length) of the electrical wave used. V V r V Itshould be understood that. screen ar-v rangements of the described kind(Figs. 9-11) act not only'as reflectors but that they ab-' sorb also aportion of thefimpinging energy; this effect is not'at all adisadvantagebecause it is also of importance to dispense of radio.-

telegraphic effect towards undesired directions and to avoid in this wayas far as possible disturbances of the radiotelegraphic; communication.i r 1 In particular casesit may be advantageous to make use of screenarrangements, and perhaps also of main emitting and receivingarrangements, of aocurved form forinstance'in case of stations where apreferreddirection of communication exists.

In Fig.12 and 13 arrangements of screens of bilateral effect. are shown.7

Fig. 12 for instance-shows twoanten'nae arrangements A and B parallel toone another and adapted'to be cut in at will and separated from oneanother by a conducting-wall C. Each antennae arrangement comprises fiveantennae 15-19 respectively 15'19'. The

right or the left antennae have to be cut in if in the right or the leftsemi-circle respectively radiotelegraphic communication is to beeffected. V e V V Aspecial advantage of this arrangement consists in thepossibility to use both antennae arrangements at the. same time fordifi'erent communications .without disturbing one by the other. a

In Fig. 13 an example of the invention is shown in which a main antennaearrangement D is positioned between twoscreen arrangements E and F (seealso Fig. 6). In this case the screen'arrangementshave to be cut inalternatively. V r In consequence of the fact, that it is possible withthe-help of arrangements according to the invention to produce withsimple means a sharply defined and directed ray. f waves, besides thepossibility of saving energy and avoiding disturbances betweendifferent'stations the additional advantage is obtained that the veryobjectionable interference efi'ects to beobservedtespecially inconnection with shortwaves may be remark-- ably diminished by: thecooperation at one receivingpoint of difierent beams travelling overdifferent paths.

If a sufficiently short wave-length is used the wholedirectionalantennae arrangement maybe built up as a rotatable unit(instead of turning the directional vector by means of time lagcircuits). This case is especially I advantageous because in alldirections use can be madeof the vector at'right angles to.

the lineof the antennae arrangement, this vector having the highestdegree of sharpness compared with all other vectors oblique tothis'line. I t o 7 As said alreadyv before the deflection of one of thetwo possible corresponding vectors may be used with. advantage inconnection with all. kinds. of bilateral. antennae a rran'gea ments andcombinations, i. e. of arrangements which are adapted to emit twoebeamsof w aves w tewards bethgdirectiens of the antennae ar 7. Ira'ngementitself, and in Which these two beams have the characteristicfeature thatin turning one ofthernthe other isltu rned in 1 the'dpposite directipn. This part of the: i

Vention is not limitedutoz the antenna arrangemore than" thpee antennaemounted zit-dis?- nee s'j'froni "'fne anetheneaehbfthe saiddieappreg'zimately-equal tq'the value i ilw iehj hi h e @iffih w iv .eiipivy afrs-siiiallilig. 1} Q i I +2.; arrangement: for directional radiom lniqation" cempri i a m p i y in Straig'htf line at .di s cesjfmm one,anQther I 1 ach of t i lSl helength ef the waveempleyedifoflsiglfnalling] I a V v mplnieation ,eemprising a multiplieity in of;mere than three; antennae l tuned to a he -x:. In, eombinatien an arqanigement: fer dii aimultiplicity I n J of; more gthjan threea'antennee,7 len'g'th' bfaitheiwaveein lbye'd' for signalling;

5 management fer shiftingtheg'vectbii ef aximumeflect."

n m "which; he .the

, pa fticnlar time Lenzpha se frelations of the An 1 arrangement fer,dineetidnal radio mmnn cat oneompr sing j a. .multipliclty n I mountidf linereithfanj thi'ee-tantennae mounted in a ipmximalealy y is taneesbeing approxi- I f1 angement {for v directional, radioqueneyJcori'espondingl to awave-length )t and iinounted in a straightline an'df'at dis} tances frein one another each'of the said disrltancesbeing 1 approximately equal to i the i 1 i be fii$1 b:d vi '1 s 1 nn--one,ti e lag-c rui -ta etien aliadie-icommunieation-comprising a}mounted at distances from 11m. another ;1 each 1 f 10f he;.'ssaiddistaneesgbein-g:vappreximatelyr in 9x is th g ling ;=a op ra fs sfiaifidi91iii nfii 'inga pangementineel ted'between thesa1dan5 1agbh a metabri se l n an arrangement for vshifting:the vecter of f maxl mnm effeetcelnpn sing means ffor adgustlng indiv dualt meintervals ,of equal valuebetween the inclividnalimpulseslin the tion efithe'maximnm vecten efintensity different antennae lfe eachi' individilal direc- 6,e01nb'in.atiQn an arrangement fondi a rectlonalrad ocqmmuneatlon,cdmpnsmg a u tiplic tym K it lnonnted'at equal distances from neanother;

each the: ai-cl distaneesbeingTapp -eximatey: to V5111? nalling; an'operaterls;station; and an" arre than 'thi eefantennee tion comprisingmeans fore adjusting indiyid- 1 I I i m1 t i itelfye i ,e eq a la uenith Y individual iimpnlses' travelling -inthe" con},

c Q ;c ni tin th enna a r nge t Y andth-e q emtotagtati'qfiwfdreaehindividnal j 3 direetien fd f ,.fth maXiinu nI Vectonintensity; I 7. 111 eoinbination"an:aprangementiffergfelt' rectiona'l.radio communication comprising :3:

other ;7 of the saiol ed at. equal distaneesl from "Qnean v Y sibein ieW h-2t isfth gthi qf he Wa p y ed fo r signalling gjan =operatofisstatien ;{and;=a"1 i compensating arrangementnsertedbetween t e ai -antnnaa r g e d ezs d op erator fsgstation the eompensating ai tange 'm nCo sist g s'u i ided a d adj sta le 1 ec r ti g: rc it i m natio vwith.sw h ng devi ef0 nn e i at willanumhzr ofsuhdivisiens of thes'aidtimecir iit w into" the c ndu g c'l d ge- "1tweenthe'antennazarrangement,an-dtheegpe f v e .ator s station; thedi'iferentjnllmbersiofgeubfa" divisionsiconlieCtedginteatheseveraltimeflag v i IQ l i on ti i1t 1gmi ple of thsm'a s 4 station g, thecompensating. ar a-ngementeoni-f V 'sistingpf snh'divideql and ad] lstahleeleetn cal me;la efii t i inzg. Qm ina e wi h" Swi ch ng onc n l ga W mum 1 r .;ber oi;subdivisiens1 of -thesaidftime lag 011 {i aicliit's [i1 b ithefienducting leadshetweenjthe" ncl J the operatorlsanten a arrangement I 0 v bdm lqne;

@ 1, the fff cohnected'into any one time lag circuit.

'10. In an arrangement for directionalrad1o COIHIHHIHCZLUOII thecombination with an antenna arrangementcomprising at least 1 threeantenna positioned inan approximate- 'ly straight'line and atequal'distances from,

one another; of a refiecting screen :built up of electricalconductorsand arranged atone side of the said-antenna arrangement and inparallelto the row of main. antennae; and

. an operators station connected to the said antenna arrangement. I

11. In an arrangement for directional radio communication thecombination with a main antenna arrangement comprising at least threeantennae tuned to a given'frequency and positioned in'an approximatelystraight line and at equal distances from one another; of afreflectingscreen built upof a plurality of antennae'tuned to the sameffrequencyand arranged at one side'of the said antennajarrangement and in paralleltothe row of mam antennae; and an operators sta by rangement.

tion connected tothe said main antenna ar- 12. In an arrangementr fordirectional'radio communication the combination with an antennaarrangement comprising i a multiplicity of antennae tuned to a' g venfrequency and 'posltioned man approximately 'stralght line and at equaldistances from oneanoth'er of areflectin'g screen arranged at one sideof5 the; antennaarrangement and built 1 up of a plurality of suspendedconductorswith indu'ctance coilsin series arranged inmparallel to therow of main antennae, the said conductors with thesaid coils beingtunedto the same frequenoygand an operators station i connected to the saidantenna arrangement.

13. In an arrangement fordirectional ra di'o communication the combinationwith an antenna arrangement according to claim 1;

' of areflectingrscreen arrangedat one side of the said. antennaarrangement and' substantially in parallelsthereto; and an operators,tstationconnect'ed' to the said antennaarrangement.

i 1 14;. In anaarrangementfor 'directionalra d1o communication the.combination with an antenna arrangement according to claim 1; of meansfor shifting the main. directional vectors of the said antennaarrangement ;'and of means'reflectingone ofthe two directional vectorstowards the direction of the other and an operators station connected tothe said antenna arrangement and the said shifting means"; v a

v15; In an arrangement for directional radio communication thecombination with an antenna arrangement for bilateral direction: alemission and reception of waves; comprising at least threesubstantially. perpendicular antennae disposed inan approximatelystraightline. andbeing tuned to a given frequency; of airefiectingscreen built up of a plurality of substantially "perpendicularconductors 'arranged'at one side of the said an-. tenna arrangement andsubstantially in parallel thereto the thickness of the said screen:being approximately equal to the wave-length a of the wavecorrespondin'gto the natural fre 'quency'oi' the antennae of the main antennaarrangement and at least one half ofthis wave-length; and ,of' anoperators station connected to the said'antenna arrangement.

* 16. In an arrangement 'for directionalirasubstantially-in parallel tothe main antennae saidperpendicular' antennae being tuned to the 7 samefrequency 'and' ipositioned at distances'f'rom one'anotlier e'qualt'o atleast one half of the Wave-length of the natural Virequencyofthe'saidantennae; and of an operators station connected: to the *saidantennaarrangement. 7 I

17. In an arrangement for directional ra diocommunicationthe combinationwith a main antenna 'farrangement according to claim '1, eachoftheindividual antennae of this arrangementbeing substantially 'perapendicular and tuned to a given frequency; of an operators station of a1 compensating means nserted between themaln antenna ar- 7 rangemen t"and the operators station and consistingof a numberoftime-lagcircuitsin dividuallyf coordinated to the, individual an- Vtennae of the said main arrangement andbuilt up of sub-divisionsofa'switching device; for cutting in at will a'number of sub-divisionsof each-time lag ciicuitvbetween the. operators station andthecorresponding antenna; and of an auxiliary antenna arrangement -po's i-.

tioned spaciallysubstantially in 'parallel to the main antenna:arrangement, each of the antennae of the auxiliary arrangementbeing"tuned to the same-nat'ural frequency as the leo fiantenneepf the mainarrangementfand the e distance between the individual antennae oftheauxiliary arrangement being substantially i equal to the Wave lengthof the said natural frequency of the antennae and at leastequal Yonehalf of this Wave-length.

die communication, twplbilateral directional antenna arrangementsaccording to cla m 1,

arrangements ,uni'lateral, said antennafarra'ngeinents'beingpositionedat both sides of g for energizing said'antennaarrangements ind i V e 18 In an arrangement for directional "ra- 1 areflecting screen for rendering said bilateral saidscre'emian operatorsstation and means dividually'at desired time periods.) f1; In testimonywhereof I aflix my signature. f t l 1 "w LT AHNEMn m CERTIFICATE orCORRECTION.

Patent No. 1,764,441. June 17, 1950.

Walter Hahnemann.

It is hereby certified that error appears in the above numbered patentrequiring correction as follows: In the drawings,$heet 4, Fig. 8, asshown below should be inserted as part of the Letters Patent and tnattne said Letters Patent should be read with this correction therein thatthe same may conform to the record of the case in the' Patent Office.

Signed and sealed this 23rd day of August, A.D. 1982.

Wm. A. Kinnan,

(Seal) I Acting Commissioner of Patents.

DISOLAI MER 1,7 64,441.Walte1" Hahnemann, Kitzeberg, near Kiel, Germany.ARRANGEMENT FOR DIRECTIONAL TRANSMISSION AND RECEPTION BY MEANS OFELECTRIC WAVES. Patent dated June 17, 1930. Disclaimer filed March 3,1932, by the assignee, Radio Corporation of America.

Therefore, enters this disclaimer relative to claims 10 and 11 of saidLetters Patent to Wit:

To the Combination 0f e le1nents set forth in claims 10 and l l of saidLetters Patent, except as the same are utllized in a system wherein theoperators station consists of adjusting means for producing a desiredphase relation in the antennae.

[Ofiicial Gazette March 22, 1932.]

